diff mbox

[gomp4] Optimize expand_omp_for_static_chunk for chunk_size one

Message ID 55DB3269.8030305@mentor.com
State New
Headers show

Commit Message

Tom de Vries Aug. 24, 2015, 3:04 p.m. UTC 
On 24-08-15 16:28, Tom de Vries wrote:
> On 24-08-15 11:43, Jakub Jelinek wrote:
>> On Mon, Jul 28, 2014 at 11:21:53AM +0200, Tom de Vries wrote:
>>> Jakub,
>>>
>>> we're using expand_omp_for_static_chunk with a chunk_size of one to expand the
>>> openacc loop construct.
>>>
>>> This results in an inner and outer loop being generated, with the inner loop
>>> having a trip count of one, which means that the inner loop can be simplified to
>>> just the inner loop body. However, subsequent optimizations do not manage to do
>>> this simplification.
>>>
>>> This patch sets the loop exit condition to true if the chunk_size is one, to
>>> ensure that the compiler will optimize away the inner loop.
>>>
>>> OK for gomp4 branch?
>>>
>>> Thanks,
>>> - Tom
>>
>>> 2014-07-25  Tom de Vries  <tom@codesourcery.com>
>>>
>>>     * omp-low.c (expand_omp_for_static_chunk): Remove inner loop if
>>>     chunk_size is one.
>>
>> If that is still the case on the trunk, the patch is ok for trunk after
>> retesting it.  Please mention the PR tree-optimization/65468 in the
>> ChangeLog entry and make sure there is some runtime testcase that tests
>> that code path (both OpenMP and OpenACC one).
>>
>
> Committed attached patch to trunk.
>
> I'll look into openacc testcase for trunk.
>

Committed as attached.

Thanks,
- Tom
diff mbox

Patch

Add libgomp.oacc-c-c++-common/vector-loop.c

2015-08-24  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/65468
	* testsuite/libgomp.oacc-c-c++-common/vector-loop.c: New test.
---
 .../libgomp.oacc-c-c++-common/vector-loop.c        | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 libgomp/testsuite/libgomp.oacc-c-c++-common/vector-loop.c

diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/vector-loop.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/vector-loop.c
new file mode 100644
index 0000000..cc915a9
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/vector-loop.c
@@ -0,0 +1,33 @@ 
+/* { dg-do run } */
+
+#include <stdlib.h>
+
+#define N 1024
+
+unsigned int a[N];
+unsigned int b[N];
+unsigned int c[N];
+unsigned int n = N;
+
+int
+main (void)
+{
+  for (unsigned int i; i < n; ++i)
+    {
+      a[i] = i % 3;
+      b[i] = i % 5;
+    }
+
+#pragma acc parallel vector_length (32) copyin (a,b) copyout (c)
+  {
+#pragma acc loop /* vector clause is missing, since it's not yet supported.  */
+    for (unsigned int i = 0; i < n; i++)
+      c[i] = a[i] + b[i];
+  }
+
+  for (unsigned int i; i < n; ++i)
+    if (c[i] != (i % 3) + (i % 5))
+      abort ();
+
+  return 0;
+}
-- 
1.9.1